This section provides background information related to the present disclosure which is not necessarily prior art.
The present disclosure relates to a floor-cleaning robot, comprising a housing, having a chassis with a drive for moving the floor-cleaning robot in a direction of travel over a surface to be cleaned, a cleaning means, which is adapted to engage with the surface to be cleaned, a control unit, and a first measuring device for three-dimensional distance measurement, which is adapted to sense the distance of the first measuring device from a plurality of surface elements within a first solid angle that is spanned from the first measuring device, wherein the control unit is adapted to guide the floor-cleaning robot over the surface to be cleaned, by means of a representation of the surface to be cleaned, and to clean the surface to be cleaned.
A floor-cleaning robot—also referred to in brief in the following as a cleaning robot or robot—is a floor-cleaning machine that has been adapted to move autonomously over a surface to be cleaned, and to clean the latter. Unlike conventional floor-cleaning machines, the robot does not depend on being actively guided by an operator over the surface to be cleaned. The robot itself determines the route along which it travels over the surface to be cleaned, and how it cleans the latter. For this, the robot obviously requires a plurality of sensors, by means of which it can sense its environment and, more precisely, the distances in relation to its environment.
A cleaning robot is known from DE 10 2011 004 319 A1 that has a chassis with a drive for moving the cleaning robot over a surface to be cleaned. The cleaning robot additionally has a cleaning means, and has a plurality of distance measuring sensors. These are both infrared and ultrasonic sensors, by means of which the point-specific distance in relation to a surface element, such as a wall or a fitment, is determined.
As used herein, the term “surface element” will be understood to mean, firstly, a portion of the surface to be cleaned, the distance from which is determined. However, it may also be a portion of a surface of an object located on the surface to be cleaned or, for example, a portion of a surface of a wall that delimits the surface to be cleaned.
For the purpose of distance measurement, the cleaning robot known from DE 10 2011 004 319 A1 uses only such distance measuring devices that, in each case, can determine the distance in relation to only one surface element located within the solid angle in which the distance measuring device is able to determine a distance. Disadvantageously, therefore, there is a need for a plurality of distance measuring devices, which can be evaluated only with large outlay in order to generate travel instructions for the cleaning robot therefrom. Moreover, the environment of the cleaning robot is sensed only with a very rough matrix, since the number of sensors is limited. Exact guidance of the robot is therefore possible only to a limited extent.
A further floor-cleaning robot is known from U.S. Pat. No. 6,667,592 B2. The cleaning robot has a plurality of distance measuring devices, which are formed, for example, as laser sensors or as ultrasonic sensors. Unlike ultrasonic sensors, which can sense the environment around the cleaning robot only in a point-specific manner, laser sensors allow sensing of the distances in relation to the environment in a plane that, for example, runs parallelwise or at an angle in relation to the surface to be cleaned. In other words, laser sensors allow sensing of distances in one dimension. The laser sensor, however, does not sense obstacles in the environment that are located outside of the sensed plane.
Finally, known from U.S. Pat. No. 8,150,650 B2 is a cleaning robot having an optical sensor by means of which images of the environment of the cleaning robot are recorded. The information that can be obtained from the images is compared with information from coupling sensors, in order to discover the position of so-called landmarks. In this way, the cleaning robot can move over a known surface to be cleaned. The use of optical sensors that do not have their own active illumination is disadvantageous, however, since the spaces in which the cleaning robot moves need to be adequately illuminated. However, active illumination in the visible spectral range can be disadvantageous, since this may cause persons to be dazzled.